From 84ba7dd71add05b52e55c60b4a3af9bb6194c73d Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 8 Dec 2017 17:01:55 +0100 Subject: [PATCH] netfilter: nf_tables: reject nat hook registration if prio is before conntrack No problem for iptables as priorities are fixed values defined in the nat modules, but in nftables the priority its coming from userspace. Reject in case we see that such a hook would not work. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 838eb581b5ab..36d38f8b0284 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1264,7 +1264,7 @@ static void nf_tables_chain_destroy(struct nft_chain *chain) struct nft_chain_hook { u32 num; - u32 priority; + s32 priority; const struct nf_chain_type *type; struct net_device *dev; }; @@ -1303,6 +1303,11 @@ static int nft_chain_parse_hook(struct net *net, } if (!(type->hook_mask & (1 << hook->num))) return -EOPNOTSUPP; + + if (type->type == NFT_CHAIN_T_NAT && + hook->priority <= NF_IP_PRI_CONNTRACK) + return -EOPNOTSUPP; + if (!try_module_get(type->owner)) return -ENOENT; -- 2.20.1